There's been a lot of question and comments while I was away, I'll try to answer them all.
1) Why do I need static IP?
Because I do.
2) How am I sure that my IP and gateway addresss are correct.
First, the gateway:
- If I type its address in a web browser, I can see the router's settings
- If I type the command "ip neigh show", I can only see this address, and it is reachable
- If I connect to the internet using "dhcpcd" and then check "ip route show", I see this address set as the gateway.
3) What does ifconfig say?
Nothing, since I do not have it.
4) Can you ping your gateway?
5) Is your gateway connected to the internet?
Yes. Note that I said I was able to connect using a dynamic IP, using the same gateway, so this is not a problem.
6) Are your gateway and IP on the same network?
7) Have you looked at the links I cited?
Some of them (didn't have the time to check them all). Didn't find anything relate to my problem specifically. Also, before posting, I search on the internet for a solution for about 2 days. Maybe I'm just bad at searching, or no one tries to do what i'm doing o_O
8) What distro are you using?
Linux From Scratch.
9) Issuing a dhcp* command seems to me to be counter-intuitive to "static host configuration." ?
YES! I totally agreed. I saw somewhere it was possible, that is what I'm trying it. I've also tried to connect using iproute2. I'm open to suggestions though.
10) Welcome to LQ?
11) What is the gateway?
A router, with eth0 as a device (no wireless).
I see a lot of examples using ifconfig, but I don't have it. I read that iproute2 is the utility to replace it (and other tools too), but I don't understand fully how it works.
I'm posting this now and will be reading some more on linux networking. Thanks for all the answers.